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SubjectRe: [BUG] scheduling while atomic when lseek()ing in /proc/net/tcp
From
Date
Tore Anderson <tore@linpro.no> writes:

> #include <sys/types.h>
> #include <sys/stat.h>
> #include <fcntl.h>
> #include <unistd.h>
> #include <stdio.h>
>
> int main(void) {
> char buf[8192];
> int fd, chars;
> fd = open("/proc/net/tcp", O_RDONLY);
> chars = read(fd, buf, sizeof(buf));
> lseek(fd, -chars+1, SEEK_CUR);
> close(fd);
> return 0;
> }

This seems to need initialization of st->state in tcp_seq_start().
tcp_seq_stop() is run with previous st->state, so it call the unneeded
unlock etc.

net/ipv4/tcp_ipv4.c | 1 +
1 files changed, 1 insertion(+)

diff -puN net/ipv4/tcp_ipv4.c~tcp_seq-oops-fix net/ipv4/tcp_ipv4.c
--- linux-2.6.0-test11/net/ipv4/tcp_ipv4.c~tcp_seq-oops-fix 2003-11-29 00:52:15.000000000 +0900
+++ linux-2.6.0-test11-hirofumi/net/ipv4/tcp_ipv4.c 2003-11-29 00:52:28.000000000 +0900
@@ -2356,6 +2356,7 @@ static void *tcp_get_idx(struct seq_file
static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
{
struct tcp_iter_state* st = seq->private;
+ st->state = TCP_SEQ_STATE_LISTENING;
st->num = 0;
return *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}
_
--
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
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